中国物理B ›› 2013, Vol. 22 ›› Issue (8): 87102-087102.doi: 10.1088/1674-1056/22/8/087102
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
刘显坤, 刘聪, 郑洲, 兰晓华
Liu Xian-Kun (刘显坤), Liu Cong (刘聪), Zheng Zhou (郑洲), Lan Xiao-Hua (兰晓华)
摘要: The structural, elastic, and thermodynamic properties of cubic-Fe2TiAl under high temperatures and pressures are investigated by performing ab initio calculation and using the quasi-harmonic Debye model. Some ground state properties such as lattice constant, bulk modulus, pressure derivative of the bulk modulus, and elastic constants are in good agreement with the available experimental results and theoretical data. The thermodynamic properties of Fe2TiAl such as thermal expansion coefficient, Debye temperature, and heat capacity in ranges of 0 K-1200 K and 0 GPa-250 GPa are also obtained. The calculation results indicate that the heat capacities at different pressures all increase with temperature increasing and are close to the Dulong-Petit limit at higher temperatures, Debye temperature decreases with temperature increasing, and increases with pressure rising. The cubic-Fe2TiAl is stable mechanically under 250 GPa. Moreover, under lower pressure, thermal expansion coefficient rises rapidly with temperature increasing, and the increasing rate becomes slow at higher pressure.
中图分类号: (Density functional theory, local density approximation, gradient and other corrections)